gfs2: Fix a number of kernel-doc warnings

Building the kernel with W=1 results in a number of kernel-doc warnings
like incorrect function names and parameter descriptions.  Fix those,
mostly by adding missing parameter descriptions, removing left-over
descriptions, and demoting some less important kernel-doc comments into
regular comments.

Originally proposed by Lee Jones; improved and combined into a single
patch by Andreas.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 2dab313..c3b00ba 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -743,7 +743,7 @@ void gfs2_clear_rgrpd(struct gfs2_sbd *sdp)
 }
 
 /**
- * gfs2_compute_bitstructs - Compute the bitmap sizes
+ * compute_bitstructs - Compute the bitmap sizes
  * @rgd: The resource group descriptor
  *
  * Calculates bitmap descriptors, one for each block that contains bitmap data
@@ -1534,8 +1534,9 @@ static void rs_insert(struct gfs2_inode *ip)
 }
 
 /**
- * rgd_free - return the number of free blocks we can allocate.
+ * rgd_free - return the number of free blocks we can allocate
  * @rgd: the resource group
+ * @rs: The reservation to free
  *
  * This function returns the number of free blocks for an rgrp.
  * That's the clone-free blocks (blocks that are free, not including those
@@ -2019,6 +2020,7 @@ static bool gfs2_select_rgrp(struct gfs2_rgrpd **pos, const struct gfs2_rgrpd *b
 
 /**
  * fast_to_acquire - determine if a resource group will be fast to acquire
+ * @rgd: The rgrp
  *
  * If this is one of our preferred rgrps, it should be quicker to acquire,
  * because we tried to set ourselves up as dlm lock master.