Fix typo in manpage.

doc/tar.1

@@ -13,7 +13,7 @@
 .\"
 .\" You should have received a copy of the GNU General Public License
 .\" along with this program.  If not, see <http://www.gnu.org/licenses/>.
-.TH TAR 1 "May 16, 2018" "TAR" "GNU TAR Manual"
+.TH TAR 1 "January 14, 2019" "TAR" "GNU TAR Manual"
 .SH NAME
 tar \- an archiving utility
 .SH SYNOPSIS
@@ -111,7 +111,7 @@ into the archive file
 verbosely listing the files being archived:
 .PP
 .EX
-.B tar cfv a.tar /etc
+.B tar cfv etc.tar /etc
 .EE
 .PP
 In
@@ -133,9 +133,9 @@ The example command above written in the
 could look like:
 .PP
 .EX
-.B tar -cvf a.tar /etc
+.B tar -cvf etc.tar /etc
 or
-.B tar -c -v -f a.tar /etc
+.B tar -c -v -f etc.tar /etc
 .EE
 .PP
 In
@@ -152,11 +152,11 @@ method.
 Here are several ways of writing the example command in this style:
 .PP
 .EX
-.B tar --create --file a.tar --verbose /etc
+.B tar --create --file etc.tar --verbose /etc
 .EE
 or (abbreviating some options):
 .EX
-.B tar --cre --file=a.tar --verb /etc
+.B tar --cre --file=etc.tar --verb /etc
 .EE
 .PP
 The options in all three styles can be intermixed, although doing so