pidfile_signal(): Return result of kill() and only remove on SIGKILL

If kill() is successful, and the signal was SIGKILL, we remove() the PID
file and return the rc of remove(), otherwise we always return the rc of
kill().

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

ChangeLog.md

@@ -9,6 +9,10 @@ All notable changes to the project are documented in this file.
 ### Changes
 - Add support for `strmatch()` and `strnmatch()`
 
+### Fixes
+- Fix `pidfile_signal()`: always return result of `kill()`, or the
+  result of `remove()` if we successfully sent `SIGKILL`
+
 
 [v2.0.2][] - 2018-05-10
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