gdb: Remove casts of NULL during assignment.

In the following code:

    struct symbol *wsym = (struct symbol *) NULL;

the cast of NULL is redundant, it adds noise, and is just one more thing
to change if the type of wsym ever changes.  There are a relatively
small number of places in gdb where the above code pattern is used.
Usually the cast is removed like this:

    struct symbol *wsym = NULL;

This commit updates all the places within the gdb/ directory where we
cast NULL during assignment, removing the cast.

gdb/ChangeLog:

	* c-valprint.c (print_unpacked_pointer): Remove cast of NULL
	pointer.
	* dbxread.c (dbx_end_psymtab): Likewise.
	* gnu-nat.c (gnu_write_inferior): Likewise.
	* mdebugread.c (cross_ref): Likewise.
	* p-valprint.c (pascal_val_print): Likewise.
	* xcoffread.c (xcoff_end_psymtab): Likewise.

1 files changed, 1 insertions, 1 deletions

diff --git a/gdb/xcoffread.c b/gdb/xcoffread.c
index 4695801..0d49751 100644
--- a/gdb/xcoffread.c
+++ b/gdb/xcoffread.c
@@ -2108,7 +2108,7 @@ xcoff_end_psymtab (struct objfile *objfile, struct partial_symtab *pst,
       discard_psymtab (objfile, pst);
 
       /* Indicate that psymtab was thrown away.  */
-      pst = (struct partial_symtab *) NULL;
+      pst = NULL;
     }
   return pst;
 }