snic: correctly check for array overrun on overly long version number

The snic version number is expected to be 4 decimals in the form like a
netmask string with each number stored in an element in array v.
However, there is an off-by-one check on the number of elements in v
allowing one to pass a 5 decimal version number causing v[4] to be
referenced, causing a buffer overrun.  Fix the off-by-one error by
comparing to i > 3 rather than 4.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NShane Seymour <shane.seymour@hpe.com>
Reviewed-by: NEwan Milne <emilne@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/snic/snic_ctl.c

@@ -75,7 +75,7 @@ snic_ver_enc(const char *s)
 			continue;
 		}
 
-		if (i > 4 || !isdigit(c))
+		if (i > 3 || !isdigit(c))
 			goto end;
 
 		v[i] = v[i] * 10 + (c - '0');