tweak whitespace to satisfy cpplint

Author: kroening

src/big-int/allocainc.h

@@ -12,13 +12,13 @@ Author: Daniel Kroening, dkr@amazon.com
 #define CPROVER_BIG_INT_ALLOCAINC_H
 
 // clang-format off
-#if defined linux || defined __linux__		\
- || defined __sun				\
- || defined UWIN				\
- || defined osf1                                \
- || defined __MACH__                            \
- || defined __CYGWIN__                          \
- || defined __EMSCRIPTEN__
+#if defined linux || defined __linux__ \
+  || defined __sun                     \
+  || defined UWIN                      \
+  || defined osf1                      \
+  || defined __MACH__                  \
+  || defined __CYGWIN__                \
+  || defined __EMSCRIPTEN__
 // clang-format on
 
 #  include <alloca.h>