[PATCH 2/4] pinctrl: Fix pinmux_hog_maps when ctrl_dev_name is not set

[Tony Lindgren <tony@atomide.com>]

The ctrl_dev_name is optional for struct pinmux_map assuming
that ctrl_dev is set. Without this patch we can get:

Unable to handle kernel NULL pointer dereference at virtual address 00000000
...
(pinmux_hog_maps+0xa4/0x20c)
(pinctrl_register+0x2a4/0x378)
...

Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/pinctrl/pinmux.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index a76a348..06b8943 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -992,9 +992,12 @@ int pinmux_hog_maps(struct pinctrl_dev *pctldev)
 
 	for (i = 0; i < pinmux_maps_num; i++) {
 		struct pinmux_map const *map = &pinmux_maps[i];
+		int match_found = 0;
 
-		if (((map->ctrl_dev == dev) ||
-		     !strcmp(map->ctrl_dev_name, devname)) &&
+		if (map->ctrl_dev_name && !strcmp(map->ctrl_dev_name, devname))
+				match_found = 1;
+
+		if (((map->ctrl_dev == dev) || match_found) &&
 		    map->hog_on_boot) {
 			/* OK time to hog! */
 			ret = pinmux_hog_map(pctldev, map);