ftrace/recordmcount: Work around for addition of metag magic but not relocations

commit b2e1c26f upstream.

glibc recently did a sync up (94e73c95d9b5 "elf.h: Sync with the gabi
webpage") that added a #define for EM_METAG but did not add relocations

This triggers build errors:

scripts/recordmcount.c: In function 'do_file':
scripts/recordmcount.c:466:28: error: 'R_METAG_ADDR32' undeclared (first use in this function)
  case EM_METAG:  reltype = R_METAG_ADDR32;
                            ^~~~~~~~~~~~~~
scripts/recordmcount.c:466:28: note: each undeclared identifier is reported only once for each function it appears in
scripts/recordmcount.c:468:20: error: 'R_METAG_NONE' undeclared (first use in this function)
     rel_type_nop = R_METAG_NONE;
                    ^~~~~~~~~~~~

Work around this change with some more #ifdefery for the relocations.

Fedora Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1354034

Link: http://lkml.kernel.org/r/1468005530-14757-1-git-send-email-labbott@redhat.com

Cc: stable@vger.kernel.org # v3.9+
Cc: James Hogan <james.hogan@imgtec.com>
Fixes: 00512bdd ("metag: ftrace support")
Reported-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

scripts/recordmcount.c

@@ -33,10 +33,17 @@
 #include <string.h>
 #include <unistd.h>
 
+/*
+ * glibc synced up and added the metag number but didn't add the relocations.
+ * Work around this in a crude manner for now.
+ */
 #ifndef EM_METAG
-/* Remove this when these make it to the standard system elf.h. */
 #define EM_METAG      174
+#endif
+#ifndef R_METAG_ADDR32
 #define R_METAG_ADDR32                   2
+#endif
+#ifndef R_METAG_NONE
 #define R_METAG_NONE                     3
 #endif