Problem reported by a downstream Cygwin user inadvertently
misconfiguring a package cross-build with mingw toolchain:

libtool with mingw hangs building openocd in
func_convert_core_msys_to_w32:

	https://cygwin.com/pipermail/cygwin/2021-June/248791.html

The issue exists in libtool build-aux/ltmain.in line 963 in
func_convert_core_msys_to_w32 Windows subshell command:

	( cmd //c echo "$1" )

see:

https://git.savannah.gnu.org/cgit/libtool.git/tree/build-aux/ltmain.in#n963

where the switch char "/" is duplicated, so instead of executing one
command in the Windows subshell context, a subshell is spawned and hangs
until manually exited e.g.:

$ cmd //c echo "$1"
Microsoft Windows [Version 10.0.19042.985]
(c) Microsoft Corporation. All rights reserved.

C:\...>exit
$

The patch merely removes the extraneous duplicated switch char "/".

As the patch is trivial, no copyright assignemnt should be required.

---
 build-aux/ltmain.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)