UPSTREAM: lib/bootconfig: Fix to remove tailing spaces after value

Fix to remove tailing spaces after value. If there is a space
after value, the bootconfig failed to remove it because it
applies strim() before replacing the delimiter with null.

For example,

foo = var    # comment

was parsed as below.

foo="var    "

but user will expect

foo="var"

This fixes it by applying strim() after removing the delimiter.

Link: https://lkml.kernel.org/r/160068149134.1088739.8868306567670058853.stgit@devnote2



Fixes: 76db5a27 ("bootconfig: Add Extra Boot Config support")
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
(cherry picked from commit c7af4ecd)
Bug: 187129171
Signed-off-by: Connor O'Brien <connoro@google.com>
Change-Id: Iff44436e31a2998c52dd97f1ba7897ddc26ae404