[PATCH v2] scripts/spdxcheck: add friendly error message for missing ply module

[3237174131]

Changes since v1:
- Remove email headers from patch body

The spdxcheck.py script requires the 'ply' Python module, but when
it is missing, the script crashes with a raw ImportError traceback.
This is especially problematic in CI environments where the error
is not immediately obvious.

Add a friendly error message that tells the user exactly what is
needed and how to install it.

Signed-off-by: Xia Zhoxin <3237174131@xxxxxx>
---
 scripts/spdxcheck.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/scripts/spdxcheck.py b/scripts/spdxcheck.py
--- a/scripts/spdxcheck.py
+++ b/scripts/spdxcheck.py
@@ -5,7 +5,13 @@
 from argparse import ArgumentParser
-from ply import lex, yacc
+try:
+    from ply import lex, yacc
+except ImportError as e:
+    import sys
+    sys.stderr.write('Error: %s\n' % e)
+    sys.stderr.write('Please install the ply module (e.g., pip install ply)\n')
+    sys.exit(1)
 import locale
 import traceback
 import fnmatch