mm: cma: use pr_err_ratelimited for CMA warning

mm: cma: use pr_err_ratelimited for CMA warning

If we did not reserve extra CMA memory, the log buffer can be easily
filled up by CMA failure warning when the devices calling
dmam_alloc_coherent() to alloc DMA memory.  Thus we can use
pr_err_ratelimited() instead to reduce the duplicate CMA warning.

Link: https://lkml.kernel.org/r/ce2251ef49e1727a9a40531d1996660b05462bd2.1615279825.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>