glusterd: Parsing key/value pair with value containing '='

Parsing key/value pair in the brickinfo file, where value contains '='
would truncate everything after '=' in value.

For example:
A key/value pair
mnt-opts=rw,noatime,allocsize=1MiB,noattr2

is parsed as:
mnt-opts=rw,noatime,allocsize

BUG: 1132451
Change-Id: I756b2fc4b06875267212b1a5c3e91c5a40c6accb
Signed-off-by: Vijaikumar M <vmallika@redhat.com>
Reviewed-on: http://review.gluster.org/8524
Reviewed-by: Sachin Pandit <spandit@redhat.com>
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Tested-by: Krishnan Parthasarathi <kparthas@redhat.com>