[PATCH V2] usb: dwc2: host: fix Wmaybe-uninitialized warning

[Nicholas Mc Guire]

Uninitialized char* causes a sparse build-warning, fix it up by
initializing it to NULL.

Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
---

V2: add missing change-log as requested by Greg Kroah-Hartman 
    <gregkh@xxxxxxxxxxxxxxxxxxx> 

Problem reported by sparse
drivers/usb/dwc2/hcd.c: In function 'dwc2_dump_urb_info':
./include/linux/dynamic_debug.h:134:3: warning: 'pipetype' may be used uninitialized in this function [-Wmaybe-uninitialized]
   __dynamic_dev_dbg(&descriptor, dev, fmt, \
   ^
drivers/usb/dwc2/hcd.c:4492:8: note: 'pipetype' was declared here
  char *pipetype;
        ^
Patch was compile tested with: x86_64_defconfig + CONFIG_USB_DWC2=m +
CONFIG_USB_DWC2_VERBOSE=y

Patch is against 4.10-rc3 (localversion-next is next-20170112)

 drivers/usb/dwc2/hcd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 911c3b3..9f66777 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -4489,8 +4489,8 @@ static void dwc2_dump_urb_info(struct usb_hcd *hcd, struct urb *urb,
 {
 #ifdef VERBOSE_DEBUG
 	struct dwc2_hsotg *hsotg = dwc2_hcd_to_hsotg(hcd);
-	char *pipetype;
-	char *speed;
+	char *pipetype = NULL;
+	char *speed = NULL;
 
 	dev_vdbg(hsotg->dev, "%s, urb %p\n", fn_name, urb);
 	dev_vdbg(hsotg->dev, "  Device address: %d\n",
-- 
2.1.4