[pushed] Remove extra space after @pxref in gdb.texinfo

[Tom Tromey <tromey@adacore.com>]

Internally at AdaCore, documentation is still built with Texinfo 4.13.
This version gave an error when building gdb.texinfo:

../../../binutils-gdb/gdb/doc/gdb.texinfo:27672: @pxref expected braces.
../../../binutils-gdb/gdb/doc/gdb.texinfo:27672: ` {dotdebug_gdb_scripts section,,The @cod...' is too long for expansion; not expanded.

... followed by many more spurious errors that were caused by this
one.

This patch fix the problem by removing the extra space.

I don't know whether it's advisable to try to support this ancient
version of Texinfo (released in 2008 apparently); but in this
particular case the fix is trivial, so I'm checking it in.

gdb/doc/ChangeLog
2021-01-27  Tom Tromey  <tromey@adacore.com>

	* gdb.texinfo (Auto-loading extensions): Remove extraneous space.
---
 gdb/doc/ChangeLog   | 4 ++++
 gdb/doc/gdb.texinfo | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index e43819f0f70..84243a72eaf 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -27669,7 +27669,7 @@ extensions when a new object file is read (for example, due to the
 library): @file{@var{objfile}-gdb.@var{ext}} (@pxref{objfile-gdbdotext
 file,,The @file{@var{objfile}-gdb.@var{ext}} file}) and the
 @code{.debug_gdb_scripts} section of modern file formats like ELF
-(@pxref {dotdebug_gdb_scripts section,,The @code{.debug_gdb_scripts}
+(@pxref{dotdebug_gdb_scripts section,,The @code{.debug_gdb_scripts}
 section}).  For a discussion of the differences between these two
 approaches see @ref{Which flavor to choose?}.
 
-- 
2.26.2