[BinaryFormat][RISCV] Ditch R_RISCV_CHERI_CAPABILITY_CALL in comment

We can just reuse R_RISCV_JUMP_SLOT when needed.

Author: jrtc27

llvm/include/llvm/BinaryFormat/ELFRelocs/RISCV.def

@@ -58,7 +58,7 @@ ELF_RELOC(R_RISCV_PLT32,             59)
 
 ELF_RELOC(R_RISCV_CHERI_CAPTAB_PCREL_HI20,        192)
 ELF_RELOC(R_RISCV_CHERI_CAPABILITY,               193)
-// 194 reserved for R_RISCV_CHERI_CAPABILITY_CALL
+// 194 reserved
 ELF_RELOC(R_RISCV_CHERI_SIZE,                     195)
 ELF_RELOC(R_RISCV_CHERI_TPREL_CINCOFFSET,         196) // Deprecated
 ELF_RELOC(R_RISCV_CHERI_TLS_IE_CAPTAB_PCREL_HI20, 197) // Deprecated