msm: pm-stats: Fix bug in computing size of a string

Use strlen and strcmp instead of sizeof and memcmp to compare strings.
procfs includes the newline character as a part of the buffer. When
using sizeof and memcmp, the newline character is used in the comparison
resulting in unequal bufferes.

Change-Id: Iafce2543596708e28757805cecae1ccec083c691
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
diff --git a/arch/arm/mach-msm/pm-stats.c b/arch/arm/mach-msm/pm-stats.c
index 936820a..675febb 100644
--- a/arch/arm/mach-msm/pm-stats.c
+++ b/arch/arm/mach-msm/pm-stats.c
@@ -188,18 +188,19 @@
 	int ret;
 	unsigned long flags;
 	unsigned int cpu;
+	size_t len = strnlen(MSM_PM_STATS_RESET, sizeof(MSM_PM_STATS_RESET));
 
 	if (count < sizeof(MSM_PM_STATS_RESET)) {
 		ret = -EINVAL;
 		goto write_proc_failed;
 	}
 
-	if (copy_from_user(buf, buffer, sizeof(MSM_PM_STATS_RESET))) {
+	if (copy_from_user(buf, buffer, len)) {
 		ret = -EFAULT;
 		goto write_proc_failed;
 	}
 
-	if (memcmp(buf, MSM_PM_STATS_RESET, sizeof(MSM_PM_STATS_RESET))) {
+	if (strncmp(buf, MSM_PM_STATS_RESET, len)) {
 		ret = -EINVAL;
 		goto write_proc_failed;
 	}