perforce: Fix path subdirectory issues

With a SRC_URI = " \
p4://depot/folder/...;module=localfolder/localsubfolder;changeslist=${P4CHANGELIST} \
"

the subfolders of //depot/folder/... get renamed when mapped to the
local folder structure. They lose the first 3 letters. This
patch fixes that.

Issue reported by and patch sent from katutxakurra@gmail.com

[YOCTO #5380]

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
data: Fix output inconsistencies for emit_var

VAL = ""     (not shown)
VAL = " "    (shown as "")
VAL = " x"   (shown as "x")

would all show up rather differently to what would be expected in the
bitbake -e output. This fixes things so they appear consistently.

The output for running some shell functions may also change slightly
but shouldn't change in a way that is likely to cause problems.

[YOCTO #5507]

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>