fix if exist path command checking for "path command" instead of path

Author: PerditionC

cmd/if.c

@@ -79,6 +79,8 @@ int cmd_if(char *param)
 		}
 
 		pp = skip_word(param);
+		*pp = '\0';
+		pp++;
 
 		/* don't show abort/retry/fail if no disk in drive */
 		get_isr(0x24, olderrhandler);