[PATCH v2] scripts/checksyscalls.sh: Add usage message, fix -Wno-error

[ritvikfoss@gmail.com]

From: Ritvik Gupta <ritvikfoss@gmail.com>

Currently 'scripts/checksyscalls.sh' does not
provide guidance when executed without specifying
a compiler, instead it attempts to execute
'-Wno-error' parameter as a command,
resulting in 'Wno-error: Command not found' error.

This patch adds a usage message that is displayed
when no compiler is provided as parameter to
improve clarity.

Signed-off-by: Ritvik Gupta <ritvikfoss@gmail.com>
---
Changes in v2:
    - Make the script posix compliant
    - Fixed formatting

Thanks for reviewing!

 scripts/checksyscalls.sh | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/scripts/checksyscalls.sh b/scripts/checksyscalls.sh
index 1e5d2eeb726d..96cba9f79249 100755
--- a/scripts/checksyscalls.sh
+++ b/scripts/checksyscalls.sh
@@ -10,6 +10,22 @@
 # checksyscalls.sh gcc gcc-options
 #
 
+usage() {
+cat << EOF
+Usage: $0 <compiler> [compiler-options]
+
+Example:
+  $0 gcc
+EOF
+
+exit 1
+}
+
+if [ $# -eq 0 ]; then
+	echo "Error: No compiler provided."
+	usage
+fi
+
 ignore_list() {
 cat << EOF
 #include <asm/types.h>
-- 
2.48.1