w3m: fix fdsan error when run on android 11

The file descriptor sanitizer keeps track of opened file descriptors
and kills programs that closes fds multiple times, or fails to close
fds.  In w3m's case a fd for a tty was obtained and saved in the ttyf
variable, but when the tty was later closed is was done using the tty
variable and not the obtained ttyf.  To my current understanding this
can lead to undesired behaviour when using multiple threads, as
another thread might write to or read from ttyf after it has been
closed.

Error looks like
fdsan: attempted to close file descriptor 3, expected to be unowned, actually owned by FILE* 0xb6c8800c

This commit fixes [1]. See also fdsan docs [2] and issue opened in the
android bug tracker [3].

[1] #6410
[2] https://android.googlesource.com/platform/bionic/+/master/docs/fdsan.md
[3] https://issuetracker.google.com/issues/184380442

packages/w3m/build.sh

@@ -5,7 +5,7 @@ TERMUX_PKG_MAINTAINER="@termux"
 _MAJOR_VERSION=0.5.3
 _MINOR_VERSION=20190105
 TERMUX_PKG_VERSION=${_MAJOR_VERSION}.${_MINOR_VERSION}
-TERMUX_PKG_REVISION=5
+TERMUX_PKG_REVISION=6
 # The upstream w3m project is dead, but every linux distribution uses
 # this maintained fork in debian:
 TERMUX_PKG_SRCURL=https://github.com/tats/w3m/archive/v${_MAJOR_VERSION}+git${_MINOR_VERSION}.tar.gz

packages/w3m/fdsan-fd-fix.patch

@@ -0,0 +1,11 @@
+--- ./terms.c.orig	2021-04-05 12:45:45.535462776 +0000
++++ ./terms.c	2021-04-05 12:45:55.075444134 +0000
+@@ -871,7 +871,7 @@
+ close_tty(void)
+ {
+     if (tty > 2)
+-	close(tty);
++	fclose(ttyf);
+ }
+
+ char *