xfs: Replace ASSERT with XFS_IS_CORRUPT in xfs_rtcopy_summary()

Replace ASSERT(sum > 0) with an XFS_IS_CORRUPT() and place it just
after the call to xfs_rtget_summary() so that we don't end up using
an illegal value of sum.

Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Author: Nirjhar-Roy-0211

fs/xfs/xfs_rtalloc.c

@@ -112,6 +112,10 @@ xfs_rtcopy_summary(
 			error = xfs_rtget_summary(oargs, log, bbno, &sum);
 			if (error)
 				goto out;
+			if (XFS_IS_CORRUPT(oargs->mp, sum < 0)) {
+				error = -EFSCORRUPTED;
+				goto out;
+			}
 			if (sum == 0)
 				continue;
 			error = xfs_rtmodify_summary(oargs, log, bbno, -sum);
@@ -120,7 +124,6 @@ xfs_rtcopy_summary(
 			error = xfs_rtmodify_summary(nargs, log, bbno, sum);
 			if (error)
 				goto out;
-			ASSERT(sum > 0);
 		}
 	}
 	error = 0;