coda: fix reference counting in coda_file_mmap error path

mmap_region() now calls fput() on the vma->vm_file.

So we need to drop the extra reference on the coda file instead of the
host file.

Link: https://lkml.kernel.org/r/20210421132012.82354-1-christian.koenig@amd.com
Fixes: 1527f926 ("mm: mmap: fix fput in error path v2")
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NJan Harkes <jaharkes@cs.cmu.edu>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: <stable@vger.kernel.org>	[5.11+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/coda/file.c

@@ -175,10 +175,10 @@ coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
 	ret = call_mmap(vma->vm_file, vma);
 
 	if (ret) {
-		/* if call_mmap fails, our caller will put coda_file so we
-		 * should drop the reference to the host_file that we got.
+		/* if call_mmap fails, our caller will put host_file so we
+		 * should drop the reference to the coda_file that we got.
 		 */
-		fput(host_file);
+		fput(coda_file);
 		kfree(cvm_ops);
 	} else {
 		/* here we add redirects for the open/close vm_operations */