staging: lustre: lprocfs: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 1271166
Addresses-Coverity-ID: 1271167
Addresses-Coverity-ID: 1271168
Addresses-Coverity-ID: 1271169
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/obdclass/lprocfs_status.c

@@ -1507,12 +1507,16 @@ int lprocfs_write_frac_u64_helper(const char __user *buffer,
 		switch (tolower(*end)) {
 		case 'p':
 			units <<= 10;
+			/* fall through */
 		case 't':
 			units <<= 10;
+			/* fall through */
 		case 'g':
 			units <<= 10;
+			/* fall through */
 		case 'm':
 			units <<= 10;
+			/* fall through */
 		case 'k':
 			units <<= 10;
 		}