MFC r334307, r335103-r335104

r334307:
Simplify macros EFPRINTF and EFFLUSH. [0]
Also stdarg(3) says that each invocation of va_start() must be paired
with a corresponding invocation of va_end() in the same function. [1]

Reported by: Coverity
CID: 1194318[0] and 1194332[1]
Discussed with: jhb
Sponsored by: iXsystems Inc.
Differential Revision: https://reviews.freebsd.org/D15548

r335103:
Fix style(9) space vs tab.

Reviewed by: jhb
Sponsored by: iXsystems Inc.
Differential Revision: https://reviews.freebsd.org/D15774

r335104:
Fix style(9) space vs tab.

Reviewed by: jhb
Sponsored by: iXsystems Inc.
Differential Revision: https://reviews.freebsd.org/D15768