Travis-CI: compiling oranif shows errors

[walter-weinmann]

from: https://travis-ci.org/KonnexionsGmbH/ora_bench/jobs/651081983

Generated jamdb_oracle app
===> Compiling oranif
mkdir -p priv
Cloning into 'odpi'...
Note: checking out '9902a60068042e7409b7806b5e73fe7e66200cae'.
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gcc -o priv/dpi_nif.so -Ic_src -I"/home/travis/otp/20.3/erts-9.3//include" -I"c_src/odpi/include" -O2 -ggdb -Wall -fPIC -std=c11 -DEMBED c_src/dpi_nif.c c_src/dpiVar_nif.c c_src/dpiStmt_nif.c c_src/dpiConn_nif.c c_src/dpiContext_nif.c c_src/dpiData_nif.c -shared
In file included from c_src/odpi/embed/dpi.c:23:0,
                 from c_src/dpi_nif.c:2:
c_src/odpi/embed/../src/dpiDebug.c: In function �dpiDebug__getFormatWithPrefix�:
c_src/odpi/embed/../src/dpiDebug.c:73:39: warning: implicit declaration of function �syscall� [-Wimplicit-function-declaration]
                 threadId = (uint64_t) syscall(SYS_gettid);
                                       ^
c_src/odpi/embed/../src/dpiDebug.c:93:21: warning: implicit declaration of function �localtime_r� [-Wimplicit-function-declaration]
                     localtime_r(&timeOfDay.tv_sec, &time);
                     ^
In file included from c_src/dpiVar_nif.h:4:0,
                 from c_src/dpiStmt_nif.c:1:
c_src/dpiStmt_nif.c: In function �stmt_fetchRows�:
c_src/dpiStmt_nif.c:139:71: warning: pointer targets in passing argument 5 of �dpiStmt_fetchRows� differ in signedness [-Wpointer-sign]
             stmtRes->stmt, maxRows, &bufferRowIndex, &numRowsFetched, &moreRows
                                                                       ^
c_src/dpi_nif.h:157:25: note: in definition of macro �RAISE_EXCEPTION_ON_DPI_ERROR�
     if (DPI_FAILURE == (_exprn))                      \
                         ^
In file included from c_src/dpi_nif.h:6:0,
                 from c_src/dpiVar_nif.h:4,
                 from c_src/dpiStmt_nif.c:1:
c_src/odpi/include/dpi.h:1612:5: note: expected �int *� but argument is of type �uint32_t * {aka unsigned int *}�
 int dpiStmt_fetchRows(dpiStmt *stmt, uint32_t maxRows,
     ^
c_src/dpiStmt_nif.c: In function �stmt_getInfo�:
c_src/dpiStmt_nif.c:514:5: warning: �type� may be used uninitialized in this function [-Wmaybe-uninitialized]
     enif_make_map_put(
     ^