Fix clang warning: implicit conversion from 'long' to 'double'

changes value from 9223372036854775807 to 9223372036854775808
[-Wimplicit-const-int-float-conversion]
        if(bytes < 0 || bytes > INT64_MAX)
                              ~ ^~~~~~~~~
/usr/include/x86/_stdint.h:90:19: note: expanded from macro 'INT64_MAX'
 #define INT64_MAX       0x7fffffffffffffff
                         ^~~~~~~~~~~~~~~~~~