ftrace: fix merge buglet

-tip testing found a bootup hang here:

  initcall anon_inode_init+0x0/0x130 returned 0 after 0 msecs
  calling  acpi_event_init+0x0/0x57

the bootup should have continued with:

  initcall acpi_event_init+0x0/0x57 returned 0 after 45 msecs

but it hung hard there instead.

bisection led to this commit:

| commit 5806b81a
| Merge: d14c8a68... 6712e299...
| Author: Ingo Molnar <mingo@elte.hu>
| Date:   Mon Jul 14 16:11:52 2008 +0200
|     Merge branch 'auto-ftrace-next' into tracing/for-linus

turns out that i made this mistake in the merge:

  ifdef CONFIG_FTRACE
  # Do not profile debug utilities
  CFLAGS_REMOVE_tsc_64.o = -pg
  CFLAGS_REMOVE_tsc_32.o = -pg

those two files got unified meanwhile - so the dont-profile annotation
got lost. The proper rule is:

  CFLAGS_REMOVE_tsc.o = -pg

i guess this could have been caught sooner if the CFLAGS_REMOVE* kbuild
rule aborted the build if it met a target that does not exist anymore?
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/Makefile

@@ -8,8 +8,7 @@ CPPFLAGS_vmlinux.lds += -U$(UTS_MACHINE)
 
 ifdef CONFIG_FTRACE
 # Do not profile debug utilities
-CFLAGS_REMOVE_tsc_64.o = -pg
-CFLAGS_REMOVE_tsc_32.o = -pg
+CFLAGS_REMOVE_tsc.o = -pg
 CFLAGS_REMOVE_rtc.o = -pg
 endif