png driver: fix typo from https://trac.osgeo.org/grass/changeset/68191

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@68194 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/pngdriver/read_png.c

@@ -64,7 +64,7 @@ void read_png(void)
 	G_fatal_error(_("Unable to allocate PNG structure"));
 
     if (setjmp(png_jmpbuf(png_ptr)))
-	G_fatal_error(_("Unable to readi PNG file"));
+	G_fatal_error(_("Unable to read PNG file"));
 
     input = fopen(png.file_name, "rb");
     if (!input)
@@ -80,7 +80,7 @@ void read_png(void)
     if (depth != 8)
 	G_fatal_error(_("Input PNG file is not 8-bit"));
 
-    if (i_width != (unsigned int)png.width || i_height != (unsigned int)png.height)
+    if (i_width != (unsigned long)png.width || i_height != (unsigned long)png.height)
 	G_fatal_error
 	    (_("Input PNG file has incorrect dimensions: expected: %dx%d got: %lux%lu"),
 	     png.width, png.height, (unsigned long) i_width, (unsigned long) i_height);