build: fix for non-standard uname

The scratchbox-based SDK for maemo cross-compilation (for Nokia N800 and N900) has a non-standard uname command which doesn't support the '-p' option.  This patch allows INSTALL to work anyway, by issuing 'uname -m' if 'uname -m -p' fails.

R=rsc
CC=plan9port.codebot
http://codereview.appspot.com/4554041
2 files changed