When the user does:

  make -C tools/perf LDFLAGS=-static

asking for a static build, and the glibc-static (or equivalent) is not
found, the message wasn't clear, stating that one of glibc-devel or
glibc-static wasn't installed, clarify it checking if -static is
present in LDFLAGS.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-7e0sfobbzgeydzi9gsz8ss3m@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>