scripts: check duplicated syscall number in syscall table

Currently, syscall{hdr,tbl}.sh sorts the entire syscall table, but you
can assume it is already sorted by the syscall number.

The generated syscall table does not work if the same syscall number
appears twice. Check it in the script.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/syscallhdr.sh

@@ -69,7 +69,7 @@ guard=_UAPI_ASM_$(basename "$outfile" |
 	sed -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/' \
 	-e 's/[^A-Z0-9_]/_/g' -e 's/__/_/g')
 
-grep -E "^[0-9A-Fa-fXx]+[[:space:]]+$abis" "$infile" | sort -n | {
+grep -E "^[0-9A-Fa-fXx]+[[:space:]]+$abis" "$infile" | {
 	echo "#ifndef $guard"
 	echo "#define $guard"
 	echo

scripts/syscalltbl.sh

@@ -52,10 +52,15 @@ outfile="$2"
 
 nxt=0
 
-grep -E "^[0-9]+[[:space:]]+$abis" "$infile" | sort -n | {
+grep -E "^[0-9]+[[:space:]]+$abis" "$infile" | {
 
 	while read nr abi name native compat ; do
 
+		if [ $nxt -gt $nr ]; then
+			echo "error: $infile: syscall table is not sorted or duplicates the same syscall number" >&2
+			exit 1
+		fi
+
 		while [ $nxt -lt $nr ]; do
 			echo "__SYSCALL($nxt, sys_ni_syscall)"
 			nxt=$((nxt + 1))