[PATCH 0/8] Fix bugs found with -D_FORTIFY_SOURCE=2

[Keith Packard]

Here's a set of 8 tiny patches which eliminate warnings that are
printed when the X server is compiled with -D_FORTIFY_SOURCE=2.

 [PATCH 1/8] test: Validate server log reading more carefully in

Actual bug fix in the test code.

 [PATCH 2/8] kdrive: Explicitly ignore errors from the -switchCmd
 [PATCH 3/8] kdrive: Ignore failure to chown console tty to current

The compiler now makes us work harder to ignore return values that we
don't care about.

 [PATCH 4/8] os: Clear the -displayfd option after closing the file

An actual bug fix -- if you use the -displayfd option and ran the
server for more than one generation, you'd end up attempting to write
the display number to a random fd after reset.

 [PATCH 5/8] os: FatalError if -displayfd writes fail

If you pass -displayfd, then we assume you actually require the
display number for the system to work right; a failure here should be
fatal instead of being silently ignored.

 [PATCH 6/8] os: Make sure that writing our pid to the lock file

We fatal error when create fails, but ignore write failures?

 [PATCH 7/8] os: Ignore log file write failures

The compiler now makes us work harder to ignore return values that we
don't care about.

 [PATCH 8/8] xkb: Verify reads of compiled keymap header and TOC

If the compiled keymap file was truncated, we would silently ignore
the errors.

-keith