west: spdx: remove unnecessary format strings

As reported by sonarqube, "String formatting should be used correctly"

Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>

Author: kartben

scripts/west_commands/spdx.py

@@ -51,12 +51,12 @@ def do_add_parser(self, parser_adder):
     def do_run(self, args, unknown_args):
         self.dbg(f"running zephyr SPDX generator")
 
-        self.dbg(f"  --init is", args.init)
-        self.dbg(f"  --build-dir is", args.build_dir)
-        self.dbg(f"  --namespace-prefix is", args.namespace_prefix)
-        self.dbg(f"  --spdx-dir is", args.spdx_dir)
-        self.dbg(f"  --analyze-includes is", args.analyze_includes)
-        self.dbg(f"  --include-sdk is", args.include_sdk)
+        self.dbg("  --init is", args.init)
+        self.dbg("  --build-dir is", args.build_dir)
+        self.dbg("  --namespace-prefix is", args.namespace_prefix)
+        self.dbg("  --spdx-dir is", args.spdx_dir)
+        self.dbg("  --analyze-includes is", args.analyze_includes)
+        self.dbg("  --include-sdk is", args.include_sdk)
 
         if args.init:
             self.do_run_init(args)