Steps to reproduce:

1. Create item proc.cpu.util[,,,No such process]
2. Compile agent with GCC hardened flags (see attachment gcc9_c_options.txt).
3. Run agent with DebugLevel=4
4. Observe in agent log

    90146:20210226:232200.270 Requested [proc.cpu.util[,,,No such process]]
    90146:20210226:232200.270 In procstat_add()
    90146:20210226:232200.270 In zbx_dshm_realloc() shmid:-1 size:21704
    90146:20210226:232200.270 In procstat_copy_data()
    90146:20210226:232200.270 End of procstat_copy_data()
    90146:20210226:232200.270 End of zbx_dshm_realloc():SUCCEED shmid:360472
    90146:20210226:232200.270 End of procstat_add()
    90144:20210226:232200.612 __zbx_zbx_setproctitle() title:'collector [processing data]'
    90144:20210226:232200.612 In update_cpustats()
    90144:20210226:232200.612 End of update_cpustats()
    90148:20210226:232200.616 In send_buffer() host:'127.0.0.1' port:10091 entries:0/100
    90148:20210226:232200.616 End of send_buffer():SUCCEED
    90148:20210226:232200.616 __zbx_zbx_setproctitle() title:'active checks #1 [idle 1 sec]'
   procstat.c:756:3: runtime error: null pointer passed as argument 1, which is declared to never be null
   procstat.c:756:3: runtime error: null pointer passed as argument 2, which is declared to never be null