Update dex_instruction.h based on compilation issue

Main issue:
In dex_instruction.h, the function is declared as:
`void dexInstr_getVarArgs(u2 *, u4[]);`

In dex_instruction.c, it is defined as:
`void dexInstr_getVarArgs(u2 *code_ptr, u4 arg[kMaxVarArgRegs])`

Known vdexExtractor issue: anestisb#89

Author: cxzero

src/dex_instruction.h

@@ -275,7 +275,7 @@ s4 dexInstr_getVRegH(u2 *);
 u2 dexInstr_getVRegH_45cc(u2 *);
 u2 dexInstr_getVRegH_4rcc(u2 *);
 bool dexInstr_hasVarArgs(u2 *);
-void dexInstr_getVarArgs(u2 *, u4[]);
+void dexInstr_getVarArgs(u2 *, u4[kMaxVarArgRegs]);
 
 // Set register functions
 void dexInstr_SetVRegA_10x(u2 *, u1);