mpfrlint: update for git.

This is used to check that the doc/mpfr.texi UPDATED-MONTH value is
up-to-date by comparing it with the date of the latest commit.

tools/mpfrlint

@@ -501,13 +501,15 @@ fi
 # Note about the TZ value: GMT0 and UTC0 are both specified by POSIX,
 # and UTC0 is the preferred value, but old systems only accept GMT0.
 # The "0" is important ("GMT" alone does not work on Tru64 Unix).
-texisvnd=`LC_ALL=C TZ=GMT0 svn info doc/mpfr.texi 2> /dev/null | sed -n 's/Last Changed Date:.*, [0-9]* \([A-Z][a-z][a-z] [0-9][0-9][0-9][0-9]\)).*/\1/p'`
-if [[ $? -eq 0 ]] && [[ -n "$texisvnd" ]] then
-  texidate=`sed -n 's/@set UPDATED-MONTH \([A-Z][a-z][a-z]\).*\( [0-9][0-9][0-9][0-9]\)/\1\2/p' doc/mpfr.texi`
-  [[ $texidate == $texisvnd ]] || { cat <<EOF && err=1 }
+#texisvnd=`LC_ALL=C TZ=GMT0 svn info doc/mpfr.texi 2> /dev/null | sed -n 's/Last Changed Date:.*, [0-9]* \([A-Z][a-z][a-z] [0-9][0-9][0-9][0-9]\)).*/\1/p'`
+texigitd=`LC_ALL=C TZ=GMT0 git show -s --format=%cd --date=format:"%B %Y" doc/mpfr.texi`
+if [[ $? -eq 0 ]] && [[ -n "$texigitd" ]] then
+  #texidate=`sed -n 's/@set UPDATED-MONTH \([A-Z][a-z][a-z]\).*\( [0-9][0-9][0-9][0-9]\)/\1\2/p' doc/mpfr.texi`
+  texidate=`sed -n 's/^@set UPDATED-MONTH *//p' doc/mpfr.texi`
+  [[ $texidate == $texigitd ]] || { cat <<EOF && err=1 }
 mpfr.texi's UPDATED-MONTH seems to be incorrect:
   mpfr.texi's UPDATED-MONTH: $texidate
-  Last Changed Date in WC:   $texisvnd
+  Last Changed Date in WC:   $texigitd
 EOF
 fi