perf tools: Fix compile of util/tsc.c

On Fedora 18, with gcc 4.6.4 compile fails with:

arch/x86/util/tsc.c: In function ‘perf_time_to_tsc’:
arch/x86/util/tsc.c:13:6: error: declaration of ‘time’ shadows a global declaration [-Werror=shadow]
cc1: all warnings being treated as errors
make: *** [/tmp/junk/arch/x86/util/tsc.o] Error 1
make: *** Waiting for unfinished jobs....

Fix by renaming the local variable.
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Link: http://lkml.kernel.org/r/1374848843-43127-1-git-send-email-dsahern@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/arch/x86/util/tsc.c

@@ -10,11 +10,11 @@
 
 u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc)
 {
-	u64 time, quot, rem;
+	u64 t, quot, rem;
 
-	time = ns - tc->time_zero;
-	quot = time / tc->time_mult;
-	rem  = time % tc->time_mult;
+	t = ns - tc->time_zero;
+	quot = t / tc->time_mult;
+	rem  = t % tc->time_mult;
 	return (quot << tc->time_shift) +
 	       (rem << tc->time_shift) / tc->time_mult;
 }