[glibc] manual: Fix strerrorname_np and strerrordesc_np return type (BZ #26343)

[glibc] manual: Fix strerrorname_np and strerrordesc_np return type (BZ #26343)

[Adhemerval Zanella]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=268ed383b57aa136d2e3a40be18a41cadba9e052

commit 268ed383b57aa136d2e3a40be18a41cadba9e052
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Fri Aug 7 16:49:59 2020 -0300

    manual: Fix strerrorname_np and strerrordesc_np return type (BZ #26343)

Diff:
---
 manual/errno.texi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/manual/errno.texi b/manual/errno.texi
index 6ca566522d..7ac1554bb1 100644
--- a/manual/errno.texi
+++ b/manual/errno.texi
@@ -1207,7 +1207,7 @@ to @code{errno}.
 The function @code{perror} is declared in @file{stdio.h}.
 @end deftypefun
 
-@deftypefun void strerrorname_np (int @var{errnum})
+@deftypefun const char * strerrorname_np (int @var{errnum})
 @standards{GNU, string.h}
 @safety{@mtsafe{}@assafe{}@acsafe{}}
 This function returns the name describing the error @var{errnum} or
@@ -1218,7 +1218,7 @@ for @code{EINVAL}).
 This function is a GNU extension, declared in the header file @file{string.h}.
 @end deftypefun
 
-@deftypefun void strerrordesc_np (int @var{errnum})
+@deftypefun const char * strerrordesc_np (int @var{errnum})
 @standards{GNU, string.h}
 @safety{@mtsafe{}@assafe{}@acsafe{}}
 This function returns the message describing the error @var{errnum} or