[OpenMP] `fopen` is not used correctly in `kmp_runtime.cpp`

[shiltian]

This is very obviously wrong (mixing fopen and O_RDONLY), and doesn't build:

/<<PKGBUILDDIR>>/openmp/runtime/src/kmp_runtime.cpp:6920:16: error: no matching function for call to 'fopen'
    FILE *tf = fopen(temp_reg_status_file_name, O_RDONLY);
               ^~~~~
/usr/include/stdio.h:270:26: note: candidate function not viable: no known conversion from 'int' to 'const char *__restrict' for 2nd argumen
extern FILE *__REDIRECT (fopen, (const char *__restrict __filename,

[llvmbot]

@llvm/issue-subscribers-openmp

[shiltian]

/cherry-pick 22cd105

[llvmbot]

Failed to cherry-pick: 22cd105

https://github.com/llvm/llvm-project/actions/runs/4264109671

Please manually backport the fix and push it to your github fork. Once this is done, please add a comment like this:

/branch <user>/<repo>/<branch>

[tstellar]

/cherry-pick 22cd105

[llvmbot]

/branch llvm/llvm-project-release-prs/issue60934