Build fix for sh3 - only built tested

[coypu]

Hi, the following seems to fix the build of
sh3 and doesn't seem to invasive.

feel free to use it, or any other solution.

I have no sh3 hardware to test it.

Index: sh3/pmap.c
===================================================================
RCS file: /cvsroot/src/sys/arch/sh3/sh3/pmap.c,v
retrieving revision 1.79
diff -u -p -u -r1.79 pmap.c
--- sh3/pmap.c  23 Dec 2016 07:15:28 -0000      1.79
+++ sh3/pmap.c  23 Dec 2016 18:20:43 -0000
@@ -128,7 +128,7 @@ vaddr_t
 pmap_steal_memory(vsize_t size, vaddr_t *vstart, vaddr_t *vend)
 {
        int npage;
-       paddr_t pa;
+       paddr_t start;
        vaddr_t va;
        uvm_physseg_t bank;
 
@@ -147,9 +147,9 @@ pmap_steal_memory(vsize_t size, vaddr_t 
        KDASSERT(uvm_physseg_valid_p(bank));
 
        /* Steal pages */
-       pa = ptoa(uvm_physseg_get_start(bank));
+       start = uvm_physseg_get_start(bank);
        uvm_physseg_unplug(start, npage);
-       va = SH3_PHYS_TO_P1SEG(pa);
+       va = SH3_PHYS_TO_P1SEG(ptoa(start));
        memset((void *)va, 0, size);
 
        return (va);