avoid possible dead loop for invalid utf8

Change-Id: Ida48b7ff119030312836aa109072ac4de7c5b9d6
diff --git a/minuitwrp/truetype.c b/minuitwrp/truetype.c
index a286449..8f62ff2 100644
--- a/minuitwrp/truetype.c
+++ b/minuitwrp/truetype.c
@@ -120,9 +120,6 @@
 
 int utf8_to_unicode(unsigned char* pIn, unsigned int *pOut)
 {
-    if(pIn == NULL || pOut == NULL)
-        return 0;
-
     int utf_bytes = 1;
     unsigned int unicode = 0;
     unsigned char tmp;
@@ -139,7 +136,11 @@
         while((tmp & 0xC0) == 0xC0)
         {
             utf_bytes ++;
-            if(utf_bytes > 6) return 0;
+            if(utf_bytes > 6)
+            {
+                *pOut = tmp;
+                return 1;
+            }
             tmp = 0xFF & (tmp << 1);
             total_bits += 6;
             high_bit_mask >>= 1;