cmd/command.c: relax length check in cmd_get_data_size()

Just check that the length is at least 2. This allows passing strings
like ".b", which can be convenient when constructing
tests (i.e. parametrizing the suffix used).

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
diff --git a/common/command.c b/common/command.c
index 83feaac..af8ffdb 100644
--- a/common/command.c
+++ b/common/command.c
@@ -470,7 +470,7 @@
 	/* Check for a size specification .b, .w or .l.
 	 */
 	int len = strlen(arg);
-	if (len > 2 && arg[len-2] == '.') {
+	if (len >= 2 && arg[len-2] == '.') {
 		switch (arg[len-1]) {
 		case 'b':
 			return 1;