Fix buffer allocation for doubled font

The problem occurs if the font height becomes greater than 32 when
doubling. Another problem is that if the height is greater than 32 then
the vpitch value becomes incorrect and cannot be loaded into the kernel.

As a solution, we need to adjust vpitch before buffer allocation.

Link: #109
Co-developed-by: Oleg Bulatov <oleg@bulatov.me>
Signed-off-by: Alexey Gladkov <legion@kernel.org>

src/libkfont/setfont.c

@@ -79,6 +79,9 @@ try_loadfont(struct kfont_context *ctx, int fd, const unsigned char *inbuf,
 		unsigned int kbytewidth = (2 * width + 7) / 8;
 		unsigned int charsize   = height * bytewidth;
 
+		if (2*height > vpitch)
+			vpitch = 2*height;
+
 		kcharsize = vpitch * kbytewidth;
 		buflen    = kcharsize * ((fontsize < 128) ? 128 : fontsize);