Bug reports from clang-analyzer

[furuame]

scan-build: Using '/usr/lib/llvm-6.0/bin/clang' for static analysis
  CC    build/curl.o
  CC    build/constants.o
  CC    build/trinary.o
  CC    build/dcurl.o
  CC    build/implcontext.o
  CC    build/pow_sse.o
src/pow_sse.c:287:16: warning: Potential leak of memory pointed to by 'c_state'
        return NULL;
               ^~~~
/usr/lib/llvm-6.0/lib/clang/6.0.0/include/stddef.h:105:24: note: expanded from macro 'NULL'
#  define NULL ((void*)0)
                       ^
src/pow_sse.c:355:16: warning: Potential leak of memory pointed to by 'c_state'
        return false;
               ^~~~~
/usr/lib/llvm-6.0/lib/clang/6.0.0/include/stdbool.h:33:15: note: expanded from macro 'false'
#define false 0
              ^
src/pow_sse.c:376:42: warning: Result of 'malloc' is converted to a pointer of type 'int8_t *', which is incompatible with sizeof operand type 'int *'
        ctx[i].nonce_array = (int8_t **) malloc(sizeof(int *) * nproc);
                              ~~~~~~~~~  ^~~~~~ ~~~~~~~~~~~~~
src/pow_sse.c:378:87: warning: Potential leak of memory pointed to by 'chunk'
        if (!ctx[i].threads || !ctx[i].pitem || !ctx[i].nonce_array || !chunk) return false;
                                                                                      ^~~~~
/usr/lib/llvm-6.0/lib/clang/6.0.0/include/stdbool.h:33:15: note: expanded from macro 'false'
#define false 0
              ^
src/pow_sse.c:378:87: warning: Potential leak of memory pointed to by 'ctx'
        if (!ctx[i].threads || !ctx[i].pitem || !ctx[i].nonce_array || !chunk) return false;
                                                                                      ^~~~~
/usr/lib/llvm-6.0/lib/clang/6.0.0/include/stdbool.h:33:15: note: expanded from macro 'false'
#define false 0
              ^
5 warnings generated.

[furuame]

@ajblane I found that the fpga implementation also has similar issue. Could you help fix it and send me a PR? Because I do not have a FPGA board to do testing.

For example:

dcurl/src/pow_fpga_accel.c

Line 42 in 5d41f9e

if (!object_trits)

The trytes object_trytes at line 36 won't be freed if branch taken at line 42.

You can reference the branch fix-memory-leak, in which I fix the SSE implementation.

[furuame]

@ajblane I found that the fpga implementation also has similar issue. Could you help fix it and send me a PR? Because I do not have a FPGA board to do testing.

For example:

dcurl/src/pow_fpga_accel.c

Line 42 in 5d41f9e
if (!object_trits)

The trytes object_trytes at line 36 won't be freed if branch taken at line 42.

You can reference the branch fix-memory-leak, in which I fix the SSE implementation.

Fixed by myself.