all: errors caught by go vet

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/5674069

misc/cgo/test/basic.go

@@ -111,7 +111,7 @@ func testErrno(t *testing.T) {
 		t.Fatalf("C.fopen: should fail")
 	}
 	if err != os.ENOENT {
-		t.Fatalf("C.fopen: unexpected error: ", err)
+		t.Fatalf("C.fopen: unexpected error: %v", err)
 	}
 }
 

test/map.go

@@ -487,7 +487,7 @@ func testbasic() {
 
 		mipM[i][i]++
 		if mipM[i][i] != (i+1)+1 {
-			fmt.Printf("update mipM[%d][%d] = %i\n", i, i, mipM[i][i])
+			fmt.Printf("update mipM[%d][%d] = %d\n", i, i, mipM[i][i])
 		}
 	}