kbuild: fix segmentation fault in modpost

[Sam Ravnborg]

If modpost was called manually with filenames without '/'
then modpost would segfault.

Signed-off-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
---
 scripts/mod/modpost.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 2b3b066..15d69c4 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1344,6 +1344,7 @@ static void add_depends(struct buffer *b, struct module *mod,
 	buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
 	buf_printf(b, "\"depends=");
 	for (s = mod->unres; s; s = s->next) {
+		const char *p;
 		if (!s->module)
 			continue;
 
@@ -1351,8 +1352,11 @@ static void add_depends(struct buffer *b, struct module *mod,
 			continue;
 
 		s->module->seen = 1;
-		buf_printf(b, "%s%s", first ? "" : ",",
-			   strrchr(s->module->name, '/') + 1);
+		if ((p = strrchr(s->module->name, '/')) != NULL)
+			p++;
+		else
+			p = s->module->name;
+		buf_printf(b, "%s%s", first ? "" : ",", p);
 		first = 0;
 	}
 	buf_printf(b, "\";\n");
-- 
1.4.4.2