Fix some quoting glitches in doc strings

This also fixes a misplaced "only".
1 job for master in 56 minutes and 40 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Test
failed #4152
test-all

00:56:40

 
Name Stage Failure
failed
test-all Test
Makefile:319: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 1
make[2]: Leaving directory '/builds/emacs/emacs/test'
make[1]: *** [check-expensive] Error 2
Makefile:294: recipe for target 'check-expensive' failed
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:959: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1