Fix comments: s/granuality/granularity/

I was grepping through the code and some `grep ganularity -R .` didn't
catch what I thought. Then looking closer I saw the term "granuality"
used in only four places (in comments) and granularity in many more
places describing the same idea. Some other facts:

dictionary.com does not know such a word
define:granuality on google is not found (and pages for granuality are
mostly related to patches to the kernel)
it has not been discussed as a term on LKML, AFAICS (=Can Search)

To be consistent, I think granularity should be used everywhere.
Signed-off-by: NKalin KOZHUHAROV <kalin@thinrope.net>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

include/linux/fs.h

@@ -864,7 +864,7 @@ struct super_block {
 	 */
 	struct mutex s_vfs_rename_mutex;	/* Kludge */
 
-	/* Granuality of c/m/atime in ns.
+	/* Granularity of c/m/atime in ns.
 	   Cannot be worse than a second */
 	u32		   s_time_gran;
 };

kernel/time.c

@@ -410,7 +410,7 @@ EXPORT_SYMBOL(current_kernel_time);
  * current_fs_time - Return FS time
  * @sb: Superblock.
  *
- * Return the current time truncated to the time granuality supported by
+ * Return the current time truncated to the time granularity supported by
  * the fs.
  */
 struct timespec current_fs_time(struct super_block *sb)
@@ -421,11 +421,11 @@ struct timespec current_fs_time(struct super_block *sb)
 EXPORT_SYMBOL(current_fs_time);
 
 /**
- * timespec_trunc - Truncate timespec to a granuality
+ * timespec_trunc - Truncate timespec to a granularity
  * @t: Timespec
- * @gran: Granuality in ns.
+ * @gran: Granularity in ns.
  *
- * Truncate a timespec to a granuality. gran must be smaller than a second.
+ * Truncate a timespec to a granularity. gran must be smaller than a second.
  * Always rounds down.
  *
  * This function should be only used for timestamps returned by