Clang warns:
drivers/i2c/busses/i2c-at91-master.c:707:6: warning: variable
'dma_buf' is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
if (dev->use_dma) {
^~~~~~~~~~~~
drivers/i2c/busses/i2c-at91-master.c:717:27: note: uninitialized use
occurs here
i2c_put_dma_safe_msg_buf(dma_buf, m_start, !ret);
^~~~~~~
Initialize dma_buf to NULL, as i2c_put_dma_safe_msg_buf() is a no-op
when the first argument is NULL, which will work for the !dev->use_dma
case.
Fixes: 03fbb903c8bf ("i2c: at91: use dma safe buffers")
Link: https://github.com/ClangBuiltLinux/linux/issues/1629
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>