go: correctly set debug-prefix-map and build directory
Go has its own system for creating temporary build
sub-directories with randomized names, and setting
up debug-prefix-map on the fly to prevent those
directories leaking into target binaries. OE's own
settings were clashing with it, so this change
carefully avoids the two stepping on each other.
Additionally, the top level build directory cannot
be named 'go-something'.
Signed-off-by: Alexander Kanavin <alex@linutronix.de> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
