Fix syntax error mysql-test-run in man page

This fixes errors like:

  $ LC_ALL=en_US.UTF-8 MANROFFSEQ='' MANWIDTH=80 \
    man --warnings -E UTF-8 -l -Tutf8 -Z mysql-test-run.pl.1 > /dev/null

  troff: <standard input>:246: warning [p 2, 6.0i, div '3tbd1,1', 0.3i]: can't break line
  troff: <standard input>:275: warning [p 2, 6.0i, div '3tbd6,1', 0.8i]: can't break line

Related to MDEV-21769.

man/mysql-test-run.pl.1

@@ -242,10 +242,7 @@ T}
 T{
 MTR_VERSION
 T}:T{
-If set to 1, will run the older version 1 of
-                \fBmysql\-test\-run\&.pl\fR\&. This will affect
-                what functionailty is available and what command line
-                options are supported\&.
+If set to 1, will run the older version 1 of \fBmysql\-test\-run\&.pl\fR\&. This will affect what functionailty is available and what command line options are supported\&.
 T}
 T{
 MTR_MEM
@@ -273,14 +270,7 @@ T}
 T{
 MTR_\fINAME\fR_TIMEOUT
 T}:T{
-Setting of a timeout in minutes or seconds, corresponding to command
-                line option
-                \fB\-\-\fR\fB\fIname\fR\fR\fB\-timeout\fR\&.
-                Available timeout names are TESTCASE,
-                SUITE (both in minutes) and
-                START, SHUTDOWN
-                (both in seconds)\&. These variables are supported from
-                MySQL 5\&.1\&.44\&.
+Setting of a timeout in minutes or seconds, corresponding to command line option \fB\-\-\fR\fB\fIname\fR\fR\fB\-timeout\fR\&. Available timeout names are TESTCASE, SUITE (both in minutes) and START, SHUTDOWN (both in seconds)\&. These variables are supported from MySQL 5\&.1\&.44\&.
 T}
 T{
 MYSQL_TEST