dmaengine: cirrus: check that output may be truncated

dmaengine: cirrus: check that output may be truncated

ep93xx_dma.c: In function 'ep93xx_dma_of_probe':
ep93xx_dma.c:1409:74: warning: '%u' directive output may be truncated
			       writing between 1 and 8 bytes into a region
			       of size 2 [-Wformat-truncation=]
		snprintf(dma_clk_name, sizeof(dma_clk_name), "m2p%u", i);
		                                                 ^~

Fixes: d7333f9d3377 ("dmaengine: cirrus: use snprintf() to calm down gcc 13.3.0")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409172024.pU8U5beA-lkp@intel.com/
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Link: https://lore.kernel.org/r/2bf9c37aad8f085839f9c63104f7275742f51945.camel@gmail.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>