microkernel: Fix fifo buffer name generation in DEFINE_FIFO

Creating FIFO using DEFINE_FIFO should result in a new buffer in noinit
section which can be used only by this particular FIFO. Currently all
FIFOs unintentionally use the same buffer (__name_buffer). Fixed FIFO
buffer name generation, so now each FIFO has its own unique buffer.

Change-Id: I7ee8250f70b141254a4c98f0ed1a7b9a29dec0c8
JIRA: ZEP-523
Signed-off-by: Mariusz Okroj <mariusz.okroj@intel.com>