libowfat: fix compilation under GCC10

Signed-off-by: Rosen Penev <rosenp@gmail.com>

libs/libowfat/Makefile

@@ -6,7 +6,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libowfat
 PKG_VERSION:=0.32
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=https://www.fefe.de/libowfat

libs/libowfat/patches/010-gcc10.patch

@@ -0,0 +1,11 @@
+--- a/io_internal.h
++++ b/io_internal.h
+@@ -83,7 +83,7 @@ my_extern array io_pollfds;
+ my_extern long first_readable;
+ my_extern long first_writeable;
+ 
+-my_extern long first_deferred;
++extern long first_deferred;
+ 
+ my_extern enum __io_waitmode {
+   UNDECIDED,