Use static_cast to cast pointers returned by malloc/calloc/realloc/mmap.

static_cast is preferable to reinterpret_cast when casting from void*
pointers returned by malloc/calloc/realloc/mmap calls.

Discovered while looking at compiler warnings (b/26936282).

Test: WITH_TIDY=1 WITH_STATIC_ANALYZER=1 mma
Change-Id: I151642d5a60c94f312d0611576ad0143c249ba3d
diff --git a/minui/graphics.cpp b/minui/graphics.cpp
index ab56a6f..d5d8d52 100644
--- a/minui/graphics.cpp
+++ b/minui/graphics.cpp
@@ -265,7 +265,7 @@
 }
 
 int gr_init_font(const char* name, GRFont** dest) {
-    GRFont* font = reinterpret_cast<GRFont*>(calloc(1, sizeof(*gr_font)));
+    GRFont* font = static_cast<GRFont*>(calloc(1, sizeof(*gr_font)));
     if (font == nullptr) {
         return -1;
     }
@@ -298,14 +298,14 @@
 
 
     // fall back to the compiled-in font.
-    gr_font = reinterpret_cast<GRFont*>(calloc(1, sizeof(*gr_font)));
-    gr_font->texture = reinterpret_cast<GRSurface*>(malloc(sizeof(*gr_font->texture)));
+    gr_font = static_cast<GRFont*>(calloc(1, sizeof(*gr_font)));
+    gr_font->texture = static_cast<GRSurface*>(malloc(sizeof(*gr_font->texture)));
     gr_font->texture->width = font.width;
     gr_font->texture->height = font.height;
     gr_font->texture->row_bytes = font.width;
     gr_font->texture->pixel_bytes = 1;
 
-    unsigned char* bits = reinterpret_cast<unsigned char*>(malloc(font.width * font.height));
+    unsigned char* bits = static_cast<unsigned char*>(malloc(font.width * font.height));
     gr_font->texture->data = reinterpret_cast<unsigned char*>(bits);
 
     unsigned char data;