mraa_iio_detect() memory leak

[jpramosi]

The function 'mraa_iio_detect()' leaks memory: #1, #2.

Proof with LeakSanitizer without line numbers, but it is obvious anyway:

=================================================================
==34795==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 96 byte(s) in 1 object(s) allocated from:
    #0 0xaaaab89d231c in __interceptor_calloc (/home/dietpi/local/ow/build/bin/mcpr+0xb231c) (BuildId: db26b1ae0f81d680a1e858a7aa504a362feb8a83)
    #1 0xffff9b7687f4 in mraa_iio_detect (/usr/local/lib/libmraa.so.2+0x97f4) (BuildId: f3fa2d24a2e40b1fbf7b52fb3b68077acbd8f3d7)
    #2 0xffff9b7681a4 in imraa_init (/usr/local/lib/libmraa.so.2+0x91a4) (BuildId: f3fa2d24a2e40b1fbf7b52fb3b68077acbd8f3d7)
    #3 0xffff9b768384 in mraa_init (/usr/local/lib/libmraa.so.2+0x9384) (BuildId: f3fa2d24a2e40b1fbf7b52fb3b68077acbd8f3d7)
    #4 0xffff9b7d4938  (/lib/ld-linux-aarch64.so.1+0xe938) (BuildId: 7368ab49979bd38b1708290d9d22f6bd4fbe2e45)
    #5 0xffff9b7d4a40  (/lib/ld-linux-aarch64.so.1+0xea40) (BuildId: 7368ab49979bd38b1708290d9d22f6bd4fbe2e45)
    #6 0xffff9b7c71c0  (/lib/ld-linux-aarch64.so.1+0x11c0) (BuildId: 7368ab49979bd38b1708290d9d22f6bd4fbe2e45)

Objects leaked above:
0xffff96201ea0 (96 bytes)

Indirect leak of 18 byte(s) in 1 object(s) allocated from:
    #0 0xaaaab89d2140 in malloc (/home/dietpi/local/ow/build/bin/mcpr+0xb2140) (BuildId: db26b1ae0f81d680a1e858a7aa504a362feb8a83)
    #1 0xffff9b7688cc in mraa_iio_detect (/usr/local/lib/libmraa.so.2+0x98cc) (BuildId: f3fa2d24a2e40b1fbf7b52fb3b68077acbd8f3d7)
    #2 0xffff9b7681a4 in imraa_init (/usr/local/lib/libmraa.so.2+0x91a4) (BuildId: f3fa2d24a2e40b1fbf7b52fb3b68077acbd8f3d7)
    #3 0xffff9b768384 in mraa_init (/usr/local/lib/libmraa.so.2+0x9384) (BuildId: f3fa2d24a2e40b1fbf7b52fb3b68077acbd8f3d7)
    #4 0xffff9b7d4938  (/lib/ld-linux-aarch64.so.1+0xe938) (BuildId: 7368ab49979bd38b1708290d9d22f6bd4fbe2e45)
    #5 0xffff9b7d4a40  (/lib/ld-linux-aarch64.so.1+0xea40) (BuildId: 7368ab49979bd38b1708290d9d22f6bd4fbe2e45)
    #6 0xffff9b7c71c0  (/lib/ld-linux-aarch64.so.1+0x11c0) (BuildId: 7368ab49979bd38b1708290d9d22f6bd4fbe2e45)

Objects leaked above:
0xffff97200220 (18 bytes)

SUMMARY: AddressSanitizer: 114 byte(s) leaked in 2 allocation(s).