drop from segments physcopy/vircopy invocations

. sys_vircopy always uses D for both src and dst
	. sys_physcopy uses PHYS_SEG if and only if corresponding
	  endpoint is NONE, so we can derive the mode (PHYS_SEG or D)
	  from the endpoint arg in the kernel, dropping the seg args
	. fields in msg still filled in for backwards compatability,
	  using same NONE-logic in the library

lib/libsys/sys_umap.c

@@ -14,7 +14,7 @@ phys_bytes *phys_addr;			/* placeholder for result */
     int result;
 
     m.CP_SRC_ENDPT = proc_ep;
-    m.CP_SRC_SPACE = seg;
+    m.UMAP_SEG = seg;
     m.CP_SRC_ADDR = vir_addr;
     m.CP_NR_BYTES = bytes;