kbuild: print only total number of section mismatces found

We have too many section mismatches detected at the moment.
So silence modpost and prevent the option from being
set in a typical allyesconfig build.

Tell the user how to see all the deteils in the summary
message from modpost.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

lib/Kconfig.debug

@@ -81,7 +81,7 @@ config HEADERS_CHECK
 
 config DEBUG_SECTION_MISMATCH
 	bool "Enable full Section mismatch analysis"
-	default n
+	depends on UNDEFINED
 	help
 	  The section mismatch analysis checks if there are illegal
 	  references from one section to another section.

scripts/mod/modpost.c

@@ -1125,15 +1125,15 @@ static void report_sec_mismatch(const char *modname, enum mismatch mismatch,
 	to = to_is_func ? "function" : "variable";
 	to_p = to_is_func ? "()" : "";
 
+	sec_mismatch_count++;
+	if (!sec_mismatch_verbose)
+		return;
+
 	fprintf(stderr, "WARNING: %s(%s+0x%llx): Section mismatch in"
 	                " reference from the %s %s%s to the %s %s:%s%s\n",
                         modname, fromsec, fromaddr, from, fromsym, from_p,
 	                to, tosec, tosym, to_p);
 
-	sec_mismatch_count++;
-	if (!sec_mismatch_verbose)
-		return;
-
 	switch (mismatch) {
 	case TEXT_TO_INIT:
 		fprintf(stderr,
@@ -1939,10 +1939,9 @@ int main(int argc, char **argv)
 		write_dump(dump_write);
 	if (sec_mismatch_count && !sec_mismatch_verbose)
 		fprintf(stderr, "modpost: Found %d section mismatch(es).\n"
-		        "To see additional details select \"Enable full "
-		        "Section mismatch analysis\"\n"
-		        "in the Kernel Hacking menu "
-		        "(CONFIG_SECTION_MISMATCH).\n", sec_mismatch_count);
+		        "To see full details build your kernel with:\n"
+		        "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
+		        sec_mismatch_count);
 
 	return err;
 }