ov5645: Fix incorrect behavior of ov5645_set_regs

The sysfs functionality of setting registers for the OV5645 camera
was broken. This is purely for development and debugging functionality
so does not fix any "real" bugs.

Change-Id: I991e1319aaf58cda66bdeac55f035f72c16b9441
diff --git a/drivers/media/platform/mxc/capture/ov5645_mipi_v2.c b/drivers/media/platform/mxc/capture/ov5645_mipi_v2.c
index 6c47f66..e1e4475 100644
--- a/drivers/media/platform/mxc/capture/ov5645_mipi_v2.c
+++ b/drivers/media/platform/mxc/capture/ov5645_mipi_v2.c
@@ -3432,7 +3432,7 @@
 	if (in_string == NULL)
 		return 0;
 
-	while (true) {
+	while (in_string != NULL) {
 		reg = strsep(&in_string, ",");
 		cnt = sscanf(reg, "%x", &reg_addr);
 		if (cnt != 1)