code review from Josh and Robert

@@ -35,38 +35,38 @@
 .Sh INTERFACE LEVEL
 illumos DDI specific
 .Sh PARAMETERS
 .Bl -tag -width Ds
 .It Fa vmp
-The vmem arena to walk
+The vmem arena to walk.
 .It Fa typemask
-A bitmask indicating the types of segment to operate on
+A bitmask indicating the types of segment to operate on.
 .Bl -tag -width Ds
 .It Dv VMEM_ALLOC
-Allocated segments
+Allocated segments.
 .It Dv VMEM_FREE
-Free segments
+Free segments.
 .El
 .It Fa func
 The function to apply to each segment matching
 .Fa typemask .
 .Fa func
-should be of 3 values and return void:
+should accept 3 arguments and return void:
 .Bl -tag -width Ds
 .It Fa "void *arg"
 The
 .Fa arg
 passed to
-.Fn vmem_walk
+.Fn vmem_walk .
 .It Fa "void *vaddr"
-The base address of the segment
+The base address of the segment.
 .It Fa "size_t size"
-The size of the segment
+The size of the segment.
 .El
 .It Fa arg
 An arbitrary argument passed to each call to
-.Fn func
+.Fn func .
 .El
 .Sh DESCRIPTION
 .Fn vmem_walk
 walks each segment in the arena
 .Fa vmp