perf build: Clarify open-coded header version warning message

In this patch we changed the header checks:

  perf build: Clarify header version warning message

Unfortunately the header checks were copied to various places and thus the message got
out of sync. Fix some of them here.

Note that there's still old, misleading messages remaining in:

  tools/objtool/Makefile: || echo "warning: objtool: x86 instruction decoder differs from kernel" >&2 )) || true
  tools/objtool/Makefile: || echo "warning: objtool: orc_types.h differs from kernel" >&2 )) || true

here objtool copied the perf message, plus:

 tools/perf/util/intel-pt-decoder/Build: || echo "Warning: Intel PT: x86 instruction decoder differs from kernel" >&2 )) || true

here the PT code regressed over the original message and only emits a vague warning
instead of specific file names...

All of this should be consolidated into tools/Build/ and used in a consistent
manner.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Francis Deslauriers <francis.deslauriers@efficios.com>
Cc: Geneviève Bastien <gbastien@versatic.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Julien Desfossez <jdesfossez@efficios.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170730095130.bblldwxjz5hamybb@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/bpf/Makefile

@@ -156,10 +156,10 @@ all_cmd: $(CMD_TARGETS)
 $(BPF_IN): force elfdep bpfdep
 	@(test -f ../../../include/uapi/linux/bpf.h -a -f ../../../include/uapi/linux/bpf.h && ( \
 	(diff -B ../../include/uapi/linux/bpf.h ../../../include/uapi/linux/bpf.h >/dev/null) || \
-	echo "Warning: tools/include/uapi/linux/bpf.h differs from kernel" >&2 )) || true
+	echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf.h' differs from latest version at 'include/uapi/linux/bpf.h'" >&2 )) || true
 	@(test -f ../../../include/uapi/linux/bpf_common.h -a -f ../../../include/uapi/linux/bpf_common.h && ( \
 	(diff -B ../../include/uapi/linux/bpf_common.h ../../../include/uapi/linux/bpf_common.h >/dev/null) || \
-	echo "Warning: tools/include/uapi/linux/bpf_common.h differs from kernel" >&2 )) || true
+	echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf_common.h' differs from latest version at 'include/uapi/linux/bpf_common.h'" >&2 )) || true
 	$(Q)$(MAKE) $(build)=libbpf
 
 $(OUTPUT)libbpf.so: $(BPF_IN)

tools/perf/arch/x86/Makefile

@@ -20,7 +20,7 @@ _dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)')
 $(header): $(sys)/syscall_64.tbl $(systbl)
 	@(test -d ../../kernel -a -d ../../tools -a -d ../perf && ( \
         (diff -B arch/x86/entry/syscalls/syscall_64.tbl ../../arch/x86/entry/syscalls/syscall_64.tbl >/dev/null) \
-        || echo "Warning: x86_64's syscall_64.tbl differs from kernel" >&2 )) || true
+        || echo "Warning: Kernel ABI header at 'tools/arch/x86/entry/syscalls/syscall_64.tbl' differs from latest version at 'arch/x86/entry/syscalls/syscall_64.tbl'" >&2 )) || true
 	$(Q)$(SHELL) '$(systbl)' $(sys)/syscall_64.tbl 'x86_64' > $@
 
 clean::