LU-8724 utils: Use open() instead of opendir() with dirfd()

Several llapi functions use opendir() and dirfd() to obtain a file
descriptor.  These calls are replaced with a single call to open().
This makes the code cleaner and more efficient.

This patch also corrects whitespace to match the Coding Style
Guidelines.

Test-Parameters: trivial
Signed-off-by: Steve Guminski <stephenx.guminski@intel.com>
Change-Id: I798165960fb500920b82adabe389975135ed3ac9
Reviewed-on: https://review.whamcloud.com/23981
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>