asn1tostruct: fix defines getting redefined

Do not write the same define twice for two files in a struct, e.g.:

  #define ENHANCEDRELOCATIONCOMPLETEREQUESTIES_RANAP_EXTENDEDRNC_ID_PRESENT                   (1 << 0)
  #define ENHANCEDRELOCATIONCOMPLETEREQUESTIES_RANAP_EXTENDEDRNC_ID_PRESENT                   (1 << 1)
  #define ENHANCEDRELOCATIONCOMPLETEREQUESTIES_RANAP_RAB_SETUPLIST_ENHANCEDRELOCCOMPLETEREQ_PRESENT (1 << 2)

  typedef struct RANAP_EnhancedRelocationCompleteRequestIEs_s {
      uint16_t                                 presenceMask;
      RANAP_IuSignallingConnectionIdentifier_t oldIuSigConId;
      RANAP_IuSignallingConnectionIdentifier_t iuSigConId;
      RANAP_GlobalRNC_ID_t                     relocation_SourceRNC_ID;
      RANAP_ExtendedRNC_ID_t                   relocation_SourceExtendedRNC_ID; ///< Optional field
      RANAP_GlobalRNC_ID_t                     relocation_TargetRNC_ID;
      RANAP_ExtendedRNC_ID_t                   relocation_TargetExtendedRNC_ID; ///< Optional field
      RANAP_RAB_SetupList_EnhancedRelocCompleteReq_t raB_SetupList_EnhancedRelocCompleteReq; ///< Optional field
  } RANAP_EnhancedRelocationCompleteRequestIEs_t;

The problem is that the type is used and it may not be unique inside a
struct. Change the code to use the name of the field if the type is not
unique. Keep using the type otherwise so existing code doesn't need to
be modified a lot to fix this.

Fix for:
../include/osmocom/ranap/ranap_ies_defs.h:514: warning: "RANAP_ENHANCEDRELOCATIONINFORMATIONREQUESTIES_RANAP_IUSIGNALLINGCONNECTIONIDENTIFIER_PRESENT" redefined

Change-Id: I2ecae6789899952d1dc5691ab76907abeaa71c12
---
M TODO-RELEASE
M asn1/utils/asn1tostruct.py
2 files changed, 28 insertions(+), 4 deletions(-)