splice: alpine build warning causing failure

header sys/errno.h gets re-directed to errno.h leading to warning and
then failure so instead directly referencing the header

Changelog-None: change header

Signed-off-by: Lakshya Singh <lakshay.singh1108@gmail.com>

common/splice_script.c

@@ -11,8 +11,8 @@
 #include <common/json_parse_simple.h>
 #include <common/splice_script.h>
 #include <ctype.h>
+#include <errno.h>
 #include <inttypes.h>
-#include <sys/errno.h>
 
 #define SCRIPT_DUMP_TOKENS 0
 #define SCRIPT_DUMP_SEGMENTS 0