gdb: Fix build for gnu hurd

Commit 695fd5ec122 ("gdb: make find_memory_region_ftype a function_view")
broke the build for gnu hurd.  Fix this.

Approved-By: Tom de Vries <tdevries@suse.de>

gdb/gnu-nat.c

diff --git a/gdb/gnu-nat.c b/gdb/gnu-nat.c
index 985aa14..4999734 100644
--- a/gdb/gnu-nat.c
+++ b/gdb/gnu-nat.c
@@ -2617,7 +2617,7 @@ gnu_nat_target::find_memory_regions (find_memory_region_ftype func)
 	  /* This region is distinct from the last one we saw, so report
 	     that previous one.  */
 	  if (last_protection != VM_PROT_NONE)
-	    (*func) (last_region_address,
+	    func (last_region_address,
 		     last_region_end - last_region_address,
 		     last_protection & VM_PROT_READ,
 		     last_protection & VM_PROT_WRITE,

gdb/gnu-nat.h

diff --git a/gdb/gnu-nat.h b/gdb/gnu-nat.h
index f4b3e3d..2ab06c8 100644
--- a/gdb/gnu-nat.h
+++ b/gdb/gnu-nat.h
@@ -130,7 +130,7 @@ struct gnu_nat_target : public inf_child_target
 					ULONGEST offset, ULONGEST len,
 					ULONGEST *xfered_len) override;
 
-  bool find_memory_regions (find_memory_region_ftype func, void *data)
+  bool find_memory_regions (find_memory_region_ftype func)
     override;
   void kill () override;