I am an idiot in km_alloc

[Artur Grabowski]

Free the correct memory when we failed to allocate va.

//art

Index: uvm/uvm_km.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_km.c,v
retrieving revision 1.97
diff -u -r1.97 uvm_km.c
--- uvm/uvm_km.c        18 Apr 2011 19:23:46 -0000      1.97
+++ uvm/uvm_km.c        19 Apr 2011 15:46:45 -0000
@@ -928,7 +928,8 @@
                while (uvm_km_pages.free == 0) {
                        if (kd->kd_waitok == 0) {
                                mtx_leave(&uvm_km_pages.mtx);
-                               uvm_pagefree(pg);
+                               if (!TAILQ_EMPTY(&pgl))
+                                       uvm_pglistfree(&pgl);
                                return NULL;
                        }
                        msleep(&uvm_km_pages.free, &uvm_km_pages.mtx, PVM,
@@ -961,6 +962,8 @@
                                tsleep(map, PVM, "km_allocva", 0);
                                goto try_map;
                        }
+                       if (!TAILQ_EMPTY(&pgl))
+                               uvm_pglistfree(&pgl);
                        return (NULL);
                }
        }