checkpatch.pl: Make CONFIG_IS_ENABLED(CONFIG_*) an error

CONFIG_IS_ENABLED() takes the kconfig name without the CONFIG_ prefix,
e.g. CONFIG_IS_ENABLED(CLK) for CONFIG_CLK. Make including the prefix
an error in checkpatch.pl so calls in the wrong format aren't
accidentally reintroduced.
Signed-off-by: NAlper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: NSimon Glass <sjg@chromium.org>

scripts/checkpatch.pl

@@ -2365,6 +2365,12 @@ sub u_boot_line {
 		ERROR("DISABLE_FDT_OR_INITRD_RELOC",
 		     "fdt or initrd relocation disabled at boot time\n" . $herecurr);
 	}
+
+	# Do not use CONFIG_ prefix in CONFIG_IS_ENABLED() calls
+	if ($line =~ /^\+.*CONFIG_IS_ENABLED\(CONFIG_\w*\).*/) {
+		ERROR("CONFIG_IS_ENABLED_CONFIG",
+		      "CONFIG_IS_ENABLED() takes values without the CONFIG_ prefix\n" . $herecurr);
+	}
 }
 
 sub process {

tools/patman/test_checkpatch.py

@@ -405,6 +405,12 @@ index 0000000..2234c87
         pm.add_line('include/myfile.h', '#include <dm.h>')
         self.checkSingleMessage(pm, 'BARRED_INCLUDE_IN_HDR', 'error')
 
+    def testConfigIsEnabledConfig(self):
+        """Test for accidental CONFIG_IS_ENABLED(CONFIG_*) calls"""
+        pm = PatchMaker()
+        pm.add_line('common/main.c', 'if (CONFIG_IS_ENABLED(CONFIG_CLK))')
+        self.checkSingleMessage(pm, 'CONFIG_IS_ENABLED_CONFIG', 'error')
+
 
 if __name__ == "__main__":
     unittest.main()