perf record: Fix mmap error output condition

The mmap_pages default value is not power of 2 (UINT_MAX).

Together with perf_evlist__mmap function returning error value different
from EPERM, we get misleading error message: "--mmap_pages/-m value must
be a power of two."

Fixing this by adding extra check for UINT_MAX value for this error
condition.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1350743599-4805-12-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-record.c

@@ -363,7 +363,8 @@ static int perf_record__open(struct perf_record *rec)
 			       "or try again with a smaller value of -m/--mmap_pages.\n"
 			       "(current value: %d)\n", opts->mmap_pages);
 			rc = -errno;
-		} else if (!is_power_of_2(opts->mmap_pages)) {
+		} else if (!is_power_of_2(opts->mmap_pages) &&
+			   (opts->mmap_pages != UINT_MAX)) {
 			pr_err("--mmap_pages/-m value must be a power of two.");
 			rc = -EINVAL;
 		} else {